(2 of 2)
Doherty and Zinkernagel showed that the white blood cells of the immune system look for changes in a key marker called the self protein, which identifies cells as belonging to one's own body. Any alterations in this protein--such as those that occur when a cell is invaded by a virus--tag the cell for destruction. Doherty and Zinkernagel's research, which won this year's Physiology or Medicine Nobel, could lead to new kinds of vaccines against cancer, multiple sclerosis and other autoimmune disorders.
ECONOMICS
Anyone who has bought a used car knows that the seller typically has far more information than the buyer. That's why states have lemon laws. Such gaps in information lie at the heart of the work for which James Mirrlees of Britain's Cambridge University, and formerly Oxford, and William Vickrey of Columbia University shared this year's Nobel for Economics. By studying the "asymmetric information" that characterizes many markets, the two men, who have never met, demolished the classic economic assumption that all parties to a deal have equal knowledge.
Each economist sketched ways to put his theoretical findings to practical use. Mirrlees, 60, who has taught in Africa, Pakistan and the U.S., devised an income-tax system that was intended to provide the maximum amount of revenue. And to the surprise of this former adviser to Britain's Labour Party, his own theory led to the conclusion that a progressive tax is not necessarily the best.
Vickrey, 82, designed a novel auction method in which bids are sealed and the winner pays what the second-highest bidder offered; a version of this is used by the U.S. Treasury to sell notes. Vickrey also urged railways and utilities to prevent congestion by charging peak rates at the busiest times of day, a practice that has now become routine.
The Canadian-born Vickrey, who died while driving to a conference three days after winning the prize, was known for his voracious curiosity and sometimes eccentric behavior. He often roller-skated from Manhattan's 125th Street train station to his classes on the Columbia campus and enjoyed sitting in on colleagues' lectures and asking pointed questions. He was keenly aware of the passage of time. "I have left undone many things that I ought to have done," he once wrote, "and can only hope that there is enough health left in me to make good some of the deficiency."